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This module has two objectives.

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The first of which is to review measures

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of disease frequency, like incidents,

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prevalence, and odds, as well as extending

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the conversation about incidents

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to things like survival analysis

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or the time until a given event occurs.

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This can get complex fast

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and your book will go
into several different

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measures of incidents that we
will also discuss together.

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One thing that I find useful

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to keep me oriented when
talking about measures

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of incidents is that the numerator

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always stays the same across

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all of the different measures.

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We only change the denominator.

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So the numerator will always be the number

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of events of interest
in whatever time period

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we're looking at.

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Changing the denominator, for example,

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talking above an incidence rate

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versus the number of persons at risk

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is just talking about the incidents

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in more and more accurate ways.

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The second objective is to
review statistical inference.

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This isn't in your book chapter,

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but it's important to review

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before we move forward and begin talking

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about measures of association
in the next module.

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We'll review statistical tests,

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like t-tests, Chi-square, and ANOVA.

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You'll see this in your lab

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and in some of the other materials below.

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Again, please reach out to me

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or Isabelle with any questions.